COLONY GROWTH IN PRIMARY CULTURES OF EHRLICH ASCITES TUMOUR USING THE AGAR METHOD FOR HUMAN BONE MARROW CULTURE

Abstract

A technique for colony formation in primary cultures of Ehrlich ascites tumour cells is described using the agar‐gel method of human bone marrow culture with human leukocytes serving as feeder cells. The colony forming efficiency was low in the primary cultures but increased rapidly by recloning of colonies upon new feeder layers at 8 days interval. Ascites tumours developed when single colonies were injected intraperitoneally into mice. In contrary to human bone marrow cultures lymphocytes or leukemic cells in the feeder layer were able to stimulate cell proliferation of Ehrlich tumour cells. Dialyzed human urine, active as a stimulator in mouse bone marrow cultures, did not stimulate Ehrlich tumour cell cultures. These findings suggests a difference, at least partly, in the nature of the feeder substance needed in the bone marrow cultures and the Ehrlich cell cultures. HeLa cells, L cells and two established Ehrlich cell lines in culture formed colonies also when cultured by the agar method. The soft agar technique offers a method for quantitative studies of drug sensitivity in primary cultures of Ehrlich ascites tumour cells and for the isolation of clones.